Final lining in mechanized excavation includes the precast concrete
segments. These segments are designed for applied loads during construction,
moving, depot, assembling in the tunnel and service loads that are affected by
earth conditions. One of these loads that are applied to the segments after
assembling in the ring, are TBM jack loads especially when the TBM should
excavate squeeze zones with single mode. As the jack pad section is smaller
than the segment section, it causes splitting loads in the segment. Symmetric
prism method is an approximate solution to evaluate these forces. In this
paper, calculated results by this method are compared to that of numerical
solution by ANSYS software. It shows 10-20
percent difference between numerical and analytical results.